Have you spent too much time waiting for large files to crawl between a computer and an external hard drive? Don't fret -- USB 3.0 has arrived. Not only can it move data faster and provide more power, but it's compatible with USB 2.0 devices.

The key to blending old and new is NEC's μPD720200 controller chip. It has the circuitry for USB 2.0 and 3.0 transfers inside and can use either, depending on what's plugged in. Right now, it's the only game in town, but look for other companies, including Symwave, Fujitsu and Via, to introduce their own USB 3.0 chips in the coming months.

The first round of USB 3.0 cards and devices works with Windows Vista and Windows 7; Apple hasn't decided whether to support the new standard. The basic software for USB 3.0 has been in the Linux kernel since last fall, and the needed drivers are slowly coming out.

There are already a few USB 3.0 devices available. To test them, I used a Lenovo ThinkPad W510 with USB 3.0 built in. I tried out a variety of new devices, including the Buffalo DriveStation USB 3.0 HD-HXU3 external hard drive; a StarTech SuperSpeed USB 3.0 to SATA Hard Drive Docking Station in combination with my current Western Digital WD Caviar Blue external drive; and a Seagate BlackArmor PS 110 USB 3.0 Performance Kit, a portable hard drive that includes its software on a USB 3.0 ExpressCard.

What's new in USB 3.0?

Unlike the change from USB 1.0 to USB 2.0, USB 3.0 brings actual physical differences to the connectors. The flat USB Type A plug (that goes into the computer) looks the same, but inside is an extra set of connectors; the edge of the plug is colored blue to indicate that it's USB 3.0.

On the other end of the cable, the Type B plug (that goes into the USB device) actually looks different -- it has an extra set of connectors, so it looks a bit like a USB plug that's been crimped a little ways down one end. There's also a new Micro Type B plug that has all its connectors laid out horizontally.

As a result, you won't be able to fit a USB 3.0 cable into a USB 2.0 device. However, you will be able to plug USB 3.0 devices -- and cables -- into your current computer; you just won't get the speed advantage. (Note: To get the most out of USB 3.0, the cable needs to be less than about 9 feet long, down from the USB 2.0 16-foot limit.)

The reason for the new connector is that the USB 3.0 cable contains nine wires (four more than a USB 2.0 cable); eight carry data and one is used as a ground. Despite the increase in wires, however, the cables should be no thicker than those used by USB 2.0. There will be a big difference in performance, however. USB 2.0 is like a single-lane country road that needs to handle the morning-commute traffic in and out of L.A. There are jams and slowdowns when too much data is going back and forth. With nine wires available, USB 3.0 has an additional two lanes of traffic in each direction to smooth the flow between the computer and the device.

Unlike USB 2.0, which requires synchronous transfers, where the data is asked for and then sent, the 3.0 host controller doesn't have to poll the USB device every time it wants to send data. This streamlines the flow with high-speed asynchronous transfers.

While SuperSpeed's peak speed is 5Gbit/sec., it will drop to a slower speed on occasion -- for example, when it moves data into and out of older devices or when it's being used with a too-long cable.

On top of faster data speeds, USB 3.0 provides up to 150 milliamps (mA) of electricity -- 50% more than USB 2.0 -- to an unconfigured device while the computer it's connected to is finding and loading its needed software. Once the device has been configured and accepted by the computer's operating system, USB 3.0 can deliver 900mA to the device, compared with USB 2.0's 500mA. This should be more than enough to power a hard drive or a camcorder -- or even a USB device (such as a monitor or a projector) that needs more power than is available via a USB 2.0 port.

USB 3.0 offers power conservation as well. While USB 2.0 is either on or off and wastes power when it isn't being used, the new spec comes with three levels of power use that draw progressively less power.

But be aware that first-generation USB 3.0 implementations are power-hungry. The Lenovo ThinkPad W510 that I used for testing ran for 2 hours 19 minutes while continuously playing music from a USB 3.0 external drive -- and ran for an additional 34 minutes when it used a USB 2.0 port.

How we tested

To gauge the abilities of the USB 3.0 spec, I connected each device to a Lenovo ThinkPad W510 that came with an Intel Core i7 processor, 8GB of RAM and a 500GB hard drive. It also has four USB ports: two USB 3.0, one USB 2.0 and one combo USB 2.0/eSATA.

Of course, the first round of USB 3.0 devices will be mostly working off of computers that still offer only USB 2.0 -- either using the 2.0 ports or using adapters that will, hopefully, bring the system up to USB 3.0 specs. I tested this by using a Fujitsu LifeBook A6220, which has a 2-GHz Core 2 Duo processor, 3GB of RAM, a 15.4-in. screen and four USB 2.0 ports. I connected each USB 3.0 device to its USB 2.0 port and then to each of two USB 3.0 ExpressCard controllers: the StarTech 2 Port ExpressCard SuperSpeed USB 3.0 Card Adapter ($50) and the USB 3.0 ExpressCard adapter that came with the Seagate BlackArmor drive.

To evaluate the speed of the three USB 3.0 devices, I used PassMark's DiskMark software, which is part of the PerformanceTest suite. The tests include:

* Sequential Read: The software creates a large test file on the external drive, and the data is read sequentially from beginning to end by the system.

* Disk Sequential Write: The software creates a large test file, and the data is sequentially written on the external hard drive.

* Disk Random Seek RW: The software creates a large test file on the external drive, and the data is read randomly. After a seek is performed to move the file pointer to a random position in the file, a 16KB block is read or written on the drive. Then the test is repeated until all the data is transferred.

* DiskMark: This weighted average score of the other tests gives a good indication of the drive's overall performance in real-world situations.

I also took an 8.45GB folder containing 1,450 files and timed how long it took to transfer them between the system and the drive. Between runs, I emptied the system's Recycle Bin.

To see if USB 2.0 devices work as promised with USB 3.0 hardware, I put together a group of 10 old and new USB 2.0 devices, including an optical drive, mouse, webcam, external hard drive, video camera, keyboard, speakers, SD card, USB key and media player. I plugged them into each of the three controllers, watched to see if they automatically connected and verified that they were working. All passed the test.

Finally, to see how the new hardware affects battery life, I played an uninterrupted stream of music from an external USB 3.0 hard drive on the ThinkPad W510 while using PassMark's BatteryMon to monitor how quickly the system's 9,500mAh battery drained. I did this using the drive with both USB 3.0 and 2.0 and compared the results.

Buffalo DriveStation USB 3.0 HD-HXU3

With its sensuously curved case and jet black finish, Buffalo's DriveStation USB 3.0 HD-HXU3 is not only stylish, it's a reliable place to stash your data.

The 1.5TB version of DriveStation ($175-$200 retail) consists of a 3.5-in. SATA drive with 1.36TB available for use. Buffalo also sells a 1TB drive for $131-$168 (retail) and a 2TB model for $244-$280 (retail).

Like the StarTech dock, the drive comes with an AC adapter. It set itself up automatically on the first try, without any additional software. I really liked its LED activity light, which glows blue for USB 3.0 and green for USB 2.0.

It also comes with a number of utilities, including Memeo backup software, a disk formatting application and a power conservation application. Throughout the testing, the DriveStation stayed cool and silent. At times, it was so quiet that I was hard-pressed to tell it was running, even while data was being transferred.

Test results

Unlike the Seagate and StarTech devices, the DriveStation did not come with a controller card (and Buffalo doesn't offer one separately). I connected the DriveStation to the Fujitsu laptop using the ExpressCards from Seagate and StarTech, and directly to the Lenovo ThinkPad W510.

When the DriveStation was plugged directly into the ThinkPad's USB 3.0 port, it had a DiskMark score of 319.9, compared with a score of 115.2 when connected to a USB 2.0 port.

The DriveStation had the best Random Read-Write speed, at 27.4Mbit/sec., which translates into sustained back-and-forth data transfers. It also did exceedingly well on Sequential Writes when paired with the StarTech card, and Sequential Reads when connected to the ThinkPad W510.

Its speed when moving the 8.45GB folder of files was in the middle range of our tested devices, with average read and write speeds of 350.2Mbit/sec. and 339.9Mbit/sec., roughly double the results when doing the same task with USB 2.0.

Bottom line

I like the way the Buffalo DriveStation looks on my desk and that it's significantly faster than USB 2.0 devices. Interestingly, the DriveStation was slower than the Seagate mobile drive on most tests involving the USB 3.0 ExpressCards; on the other hand, it did slightly better than the Seagate when plugged directly into the USB 3.0-equipped ThinkPad.

Seagate BlackArmor PS 110 USB 3.0 Performance Kit

Seagate's BlackArmor PS 110 USB 3.0 Performance Kit ($180) can make mobile data move a lot faster. Small enough to go where you go, the 500GB portable drive is a convenient way to carry around your files and/or backups.

At 0.5 by 3.2 by 5.1 in. and weighing 6.2 oz., the PS 110 is about the same size as other portable drives, such as Western Digital's My Passport Essential drive. Inside is a 2.5-in. SATA drive that spins at 7,200rpm and yields 465GB of usable space.

The BlackArmor kit includes its own ExpressCard adapter so that you can enjoy USB 3.0 speeds on a USB 2.0 laptop; the card offers a single USB 3.0 connector (not quite as convenient as the StarTech card, which gives you a pair of USB 3.0 slots). It also requires a second USB connection on the host computer to power the drive.

The BlackArmor drive installed its drivers automatically when I plugged the unit into the computers. The ExpressCard adapter also set itself up without any problems and connected with both the USB 3.0 and USB 2.0 devices neatly.

The drive comes with Seagate's BlackArmor backup program and 256-bit AES encryption software for scrambling your files so only you can read them. When data is being transferred onto or off of the drive, its LED glows blue; however, unlike the DriveStation, the BlackArmor drive doesn't indicate whether you're running it as a USB 2.0 or USB 3.0 device.

Unlike the other two drives tested here, which use a full-sized USB 3.0 plug, the BlackArmor uses a Micro USB 3.0 plug. In my testing, the drive worked dependably with the StarTech and Seagate ExpressCard adapters and with the ThinkPad W510.

Test results

With the drive plugged directly into the ThinkPad's USB 3.0 port, the BlackArmor had a DiskMark score of 275.4, just a bit slower than both the Buffalo DriveStation and the StarTech Dock with the Western Digital drive. However, it sped ahead when connected to the StarTech USB 3.0 ExpressCard with a score of 432.9, the highest DiskMark score in these tests.

The drive's Sequential Read and Write scores were also the fastest of the group, with 466Mbit and 468Mbit/sec. of throughput respectively, about three times the speed it delivers with USB 2.0.

On the downside, it was the slowest of our three test drives when it came to reading and writing the 8.45GB folder of assorted files, with speeds of 287.6Mbit and 207.4Mbit/sec.

Bottom line

At $180 (direct) for 500GB, including an ExpressCard adapter, the BlackArmor PS 110 is a good buy that can open up the benefits of USB 3.0 for those who are on the go or on a budget.

StarTech SuperSpeed USB 3.0 to SATA Hard Drive Docking Station

Let's say you already have a good hard drive with all your data on it, and all you want to do is speed it up to USB 3.0 speeds. StarTech's inexpensive SuperSpeed USB 3.0 to SATA Hard Drive Docking Station is a good place to start. At $76, it can goose your drive to top speed.

The beauty of the StarTech dock is that it works with both 2.5- and 3.5-in. SATA drives. It's also easy to install: The drive drops right in through a hinged door that gives way as it enters the dock. There's no software to load -- just turn the dock on; as data starts moving back and forth, the power light in the switch goes from blue to purple. (However, it's not as cool as the Buffalo's light, which indicates whether the device is connected to a USB 2.0 or 3.0 port.)

The drive dock comes with a 3-foot USB 3.0 cable, and StarTech sells a USB 3.0 ExpressCard adapter for $50. The card has two USB 3.0 ports, unlike the Seagate card's single port. The dock automatically connected with the ThinkPad W510 and both of the ExpressCard adapters I used.